FIELD TO WHICH THE INVENTION PERTAINS
In transporting articles of various kinds, e.g., washing machines or other large consumer appliances, the articles are usually placed in the cargo space of a vehicle such as a railroad car. After placing the articles in the car, it is desirable to prevent them from being damaged due to their shifting or moving around during transport. Dunnage bags, large air-inflatable bags often made of paper with an air-tight plastic liner, are a means of preventing such movement, and are used by many carriers. These bags are placed between the articles to be shipped and between the articles and the walls of the cargo space and then inflated. The inflated bags provide a resilient cushion between articles and between the articles and the walls of the cargo space. At the destination, the dunnage bags are deflated and removed to facilitate unloading of the articles.
Often it is desirable to set the uninflated dunnage bags in place before the vehicle is loaded, and then to load the articles into the cargo space around the bags. The bags are then inflated to hold the load in place.
This procedure of loading around the uninflated dunnage bags permits the voids between articles and between the articles and the cargo space walls to be kept to a minimum. If the dunnage bags were to be placed in position after the vehicle was loaded, voids between the articles and between the articles and the walls of sufficient size to provide a walkway for a person positioning the bags would be required. With the bags in place before the vehicle is loaded, much smaller voids between the articles and between the articles and the cargo space walls are necessary. Thus valuable vehicle cargo space is conserved and when the bags are inflated the load is more snugly held in place if the bags are positioned before the vehicle is loaded.
In the face of rising transportation costs, disposable dunnage bags which may be deflated and discarded when the articles reach their destination are preferred. Because the disposable bags are used only once and then discarded, the art has tried to minimize their cost. Typically, the bags are constructed of inexpensive materials, e.g., paper webs or sheets encasing a bladder made from a thin thermo-plastic material. Another way in which low cost has been achieved is to provide bags in certain standard sizes which must accommodate all configurations of loads and vehicle cargo spaces. Also, because one large dunnage bag is less expensive than two smaller bags which occupy the same volume when inflated, the objective of minimizing costs has led to the use of larger bags.
Dunnage bags which are 16 feet in length are commonly used in rail freight car applications. Typically, more than one of the 16 foot long bags must be set in place and inflated to provide restraint against shifting of the load in a fully loaded freight car. These 16 foot bags are cumbersome to set in place initially, and are difficult to keep in place prior to and during inflation.
While the art has addressed itself to the attachment and placement of inflatable dunnage bags in vehicles before the vehicles are loaded, the typical arrangement is not suitable for disposable paper dunnage bags of the types which are now popular. Thus the invention disclosed herein facilitates the use of dunnage bags in vehicles which are not specially equipped with bag-supporting mechanisms. Finally it is contemplated that the invention described herein is especially suited for use with dunnage bags of various standard sizes and shapes, which can be used in different combinations to accommodate loads which vary in geometric configuration and is particularly well-suited for use with long dunnage bags which are so difficult and cumbersome to set and hold in place.